Prove each of the following identities:

(cosec θ)(1 + cos θ)(cosec θ – cot θ) = 1

Consider the left – hand side:

L.H.S. = (cosec θ) (1 + cos θ)(cosec θ – cot θ)


= (1 – cos2 θ) × cosec2 θ


( 1 + cot2 θ = cosec2 θ)


= (sin2 θ) × cosec2 θ


( sin2θ + cos2 θ = 1)


= 1


= R.H.S.


Hence, proved.


4